An internet of things (IoT) as a new information communication infrastructure to network all things existing in the world to communicate among humans and/or objects with one another anytime or anywhere means an infrastructure for realizing a ubiquitous space. The ubiquitous space starts with environments and objects having computing devices with which specific functions are equipped, built in to allow the environments or the objects themselves to be intellectualized.
The IoT is a technology, which provides more convenient and safe life for us. FIGS. 1 and 2 illustrate implementation examples of the IoT. The IoT may be variously implemented, but referring to FIG. 1, implemented by a plurality of electronic apparatus 1a to 1d to detect surrounding environments and a user terminal 2 to receive the detected surrounding environment information from the plurality of electronic apparatus 1a to 1d. A user may receive the information detected by the plurality of electronic apparatus 1a to 1d in various types, for example, such as images, voices and so on, via the user terminal 2. Also, referring to FIG. 2, the IoT may be implemented in the form of a plurality of electronic apparatus 1e to 1i and a user terminal 2 to provide a command to the plurality of electronic apparatus 1e to 1i or to receive information from the plurality of electronic apparatus 1e to 1i. That is, the user may receive conditions or the like of the plurality of electronic apparatus 1e to 1i via the user terminal 2, and transmit a control command for changing conditions or operations of the plurality of electronic apparatus 1e to 1i using the user terminal 2. The IoT is not limited to the drawings and explanations as described above and may be implemented as various electronic apparatuses 1a to 1i and a user terminal 2 for controlling those electronic apparatuses 1a to 1i. 
Referring to FIG. 4, there is illustrated an example in which a plurality of electronic apparatuses 1a to 1f provides information for a user terminal 2 via a server 4. The plurality of electronic apparatuses 1a to 1f may not only directly provide the information for the user terminal 2, but also as illustrated in the drawing, for a server 4 connected to a network or the like, so that the user in turn receives the information via the server 4.
In other words, the plurality of electronic apparatuses 1a to 1f periodically attempts accesses to the server 4 and if acknowledgements are received, transmits detected information, respectively.
Even if the server 4 cannot acknowledge the accesses of the electronic apparatuses 1a to 1f since it is in an uncommunicable state due to errors, communication congestion, power degradation or the like, the plurality of electronic apparatuses 1a to 1f periodically attempts accesses to the server 4 until the server 4 transmits the acknowledgements. As a result, there is a problem in that channel contention and power consumption in the respective electronic apparatuses 1a to 1f may occur.
Methods and apparatuses consistent with exemplary embodiments relate an electronic apparatus, which if a server does not respond, spreads a signal to other electronic apparatuses to restrict accesses thereof to the server, and a control method thereof.
In accordance with an aspect of an exemplary embodiment, there is provided an electronic apparatus having a plurality of operation modes with respect to an access to a server, the apparatus including: an information generator configured to generate information used to one function of a user terminal; a communicator configured to communicate with the user terminal, the server and a plurality of external apparatuses having the plurality of operation modes; and a controller configured to control the communicator: to attempt an access to the server at a first operation mode; in response to determining that the server is in a normal communication state based on the access attempt, to provide information generated by the information generator to the user terminal via the server; and in response to determining that the server is in a communication pending state based on the access attempt, to transmit a first mode changing signal for operating in a second operation mode, which restricts the access to the server, to at least one of the plurality of external apparatuses.
The controller may be more preferably configured to, in response to the first mode change signal being received from at least one of the plurality of external apparatuses via the communicator at the first operation mode, determine that the server is in the communication pending state, to control the communicator to transmit the first mode change signal to at least one of the plurality of external apparatuses and to change an operation mode of the electronic apparatus to the second operation mode.
The controller may be more preferably configured to restrict the operation of the information generator at the second operation mode.
The controller may be more preferably configured, in response to a second mode change signal for operating in the first operation mode being received from at least one of the plurality of external apparatuses via the communicator at the second operation mode, to control the communicator to transmit the second mode change signal to at least one of the plurality of external apparatuses and to change the operation mode of the electronic apparatus to the first operation mode.
The controller may be more preferably configured to control the communicator to periodically attempt the access to the server at the first operation mode.
The controller may be more preferably configured to determine that the server is in the communication pending state in response to a communication acknowledgement being not received from the server while attempting the access to the server more than predetermined critical number of times.
The controller may be more preferably configured to, in response to determining that the server is in the normal communication state based on the periodical access attempts after transmitting the first mode change signal to the at least one of the plurality of external apparatuses, control the communicator to transmit a second mode change signal for operating in the first mode to the at least one external apparatus to which the first mode change signal is transmitted.
The information used to the one function of the user terminal may more preferably include at least one of surrounding environment information and information on current condition of the electronic apparatus.
The apparatus may be more preferably further include a storage configured to store the information used to the one function of the user terminal, and the controller may be more preferably configured to, in response to determining that the server is in the communication pending state based the access attempt or operating in the second mode, store in the storage, the information used to the one function of the user terminal.
The controller may be more preferably configured to control the communicator to retrieve whether there is any external apparatus capable of storing information from among the plurality of external apparatuses and to transmit the information used to the one function of the user terminal to the retrieved external apparatus.
The controller may be more preferably configured to control the electronic apparatus to change the operation mode based on a predetermined cycle.
The predetermined cycle may be more preferably set based on locations of the electronic apparatus and the plurality of external apparatuses.
In accordance with an aspect of another exemplary embodiment, there is provided a control method of an electronic apparatus having a plurality of operation modes with respect to an access to a server, the method including: generating information used to one function of a user terminal; attempting an access to the server at a first operation mode; in response to determining that the server is in a normal communication state based on the access attempt, providing the generated information to the user terminal via the server; and in response to determining that the server is in a communication pending state based on the access attempt, transmitting a first mode changing signal for operating in a second operation mode, which restricts the access to the server, to at least one of the plurality of external apparatuses.
The method may more preferably further include, in response to the first mode change signal being received from at least one of the plurality of external apparatuses at the first operation mode, determining that the server is in the communication pending state; transmitting the first mode change signal to at least one of the plurality of external apparatuses; and changing an operation mode of the electronic apparatus to the second operation mode.
The method may more preferably further include restricting the information generating operation at the second operation mode.
The method may more preferably further include, in response to a second mode change signal for operating in the first operation mode being received from at least one of the plurality of external apparatuses at the second operation mode, transmitting the second mode change signal to at least one of the plurality of external apparatuses and changing the operation mode of the electronic apparatus to the first operation mode.
The method may more preferably further include periodically attempting the access to the server.
The periodically attempting may more preferably include determining that the server is in the communication pending state in response to a communication acknowledgement being not received from the server while attempting the access to the server more than predetermined critical number of times.
The method may more preferably further include, in response to determining that the server is in the normal communication state based on the periodical access attempts after transmitting the first mode change signal to the at least one of the plurality of external apparatuses, transmitting a second mode change signal for operating in the first mode to the at least one external apparatus to which the first mode change signal is transmitted.
The information used to the one function of the user terminal may more preferably include at least one of surrounding environment information and information on current condition of the electronic apparatus.
The method may more preferably further include, in response to determining that the server is in the communication pending state based the access attempt or operating in the second mode, storing the information used to the one function of the user terminal.
The method may more preferably further include retrieving whether there is any external apparatus capable of storing information from among the plurality of external apparatuses and transmitting the information used to the one function of the user terminal to the retrieved external apparatus.
The method may more preferably further include changing the operation mode of the electronic apparatus based on a predetermined cycle.
According to the exemplary embodiments, if the server does not respond, the electronic apparatus may spreads the signal to other surrounding electronic apparatuses to restrict accesses to the server, thereby enhancing electric power and communication efficiencies.